3 Acids, Bases & Buffers Flashcards
Dynamic Equilibrium
- ) most chemical reactions are reversible
- ) reactants combine to give products
- ) products can fall apart to give reactants
Le Chatelier’s Principle
-when a system in a state of dynamic equilibrium is disturbed (meds), it will react to re-establish equilibrium conditions
The Equilibrium Constant
- a system is in a state of equilibrium when there is a balance between reactants and products
- mathematical, numerical description of the balance
- pKa
K
state of equillibrium
As K increases…
reaction tends to shift towards products
As K decreases..
reaction tends to shift towards starting materials
Subscript Keq
generic equilibrium constant
Subscript Ka
weak acids
Subscript Kb
weak bases
Subscript Ksp
solubility
Bronstead: Acid
-a proton/hydrogen ion donor
Bronstead: Base
-a proton/hydrogen ion acceptor
Conjugate Base
when an acid donates a proton, it is converted into its conjugate base
Conjugate Acid
when a base accepts a proton, is becomes a conjugate acid
Amphoteric Species
- can behave as an acid or a base
- ex.) water
The stronger the acid…
the weaker the conjugate base
*more determined to give its proton to some base
“rly pushy
The weaker the acid…
the stronger the conjugate base
ion
atom or molecule w/ net electrical charge d/t loss or gain of electrons
ionize
conversion of an ion by removing ion/ions
nonionized
uncharged, lipophilic
ionized
charge, hydrophilic
3 steps to determine drug nature
- ) is the drug weak acid or weak base?
- ) what is the pKa of the drug
- ) the pH of the target solution
Naming weak acids
salt drugs - sodium drug, calcium drug, magnesium drug
-salt base form of a weak acid, increased solubility
Naming weak bases
drug chloride, drug sulfate
-salt form of weak base
Weak Acid examples
thiopental, sodium phenobarbital
Weak Base examples
local (lidocaine), morphine, versed
Fetal pH
- more acidic
- more likely to trap ions
